U.S. patent application number 16/594956 was filed with the patent office on 2020-04-09 for cutting tool.
This patent application is currently assigned to GUEHRING KG. The applicant listed for this patent is GUEHRING KG. Invention is credited to Michael BOPP.
Application Number | 20200108448 16/594956 |
Document ID | / |
Family ID | 62486586 |
Filed Date | 2020-04-09 |
United States Patent
Application |
20200108448 |
Kind Code |
A1 |
BOPP; Michael |
April 9, 2020 |
CUTTING TOOL
Abstract
A cutting tool comprising at least one blade arranged at an
axial cutting head end of a tool carrier. The tool carrier
comprises a chip-removal space that receives material chips removed
by the blade. In some embodiments, the blade is adjacent to a chip
passage feeding into the chip-removal space, which passage is
limited by a radial chip gap partially limited by the blade and
from there by a first and second passage surface, the first passage
surface a continuation of the chip surface of the blade, the second
passage surface running at an angle and widening relative to same,
and is closed and limited at least in an axial sub-section facing
the cutting head end, all around by a peripheral wall as a third
passage surface, wherein at least one coolant channel is formed
within the peripheral wall, which is provided to guide coolant to
the cutting head end.
Inventors: |
BOPP; Michael;
(Sigmaringen-Laiz, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GUEHRING KG |
Albstadt |
|
DE |
|
|
Assignee: |
GUEHRING KG
Albstadt
DE
|
Family ID: |
62486586 |
Appl. No.: |
16/594956 |
Filed: |
October 7, 2019 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
PCT/EP2018/064252 |
May 30, 2018 |
|
|
|
16594956 |
|
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B23B 27/10 20130101;
B23B 2270/30 20130101; B23B 2200/323 20130101; B23D 77/006
20130101; B23B 2200/328 20130101; B23B 2250/12 20130101; B23C 5/28
20130101; B23D 2277/30 20130101; B23B 2251/50 20130101; B23C
2250/12 20130101; B23B 51/06 20130101 |
International
Class: |
B23B 27/10 20060101
B23B027/10; B23B 51/06 20060101 B23B051/06; B23C 5/28 20060101
B23C005/28 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 8, 2017 |
DE |
10 2017 112 696.1 |
Claims
1. A cutting tool, comprising a clamping shank and a tool carrier
comprising a cutting head and at least one blade, which is arranged
at an axial cutting head end of the tool carrier, wherein the tool
carrier comprises a chip-receiving space, which is molded to
receive material chips of a component to be processed removed by
the blade, wherein a respective chip passage, which feeds into the
chip-receiving space and which is limited by a chip gap, which runs
radially and which is partially limited by the blade, and from
there by a first and second passage surface extending in the
direction of the chip-receiving space, adjoins the at least one
blade, wherein the first passage surface is a continuation of the
chip surface of the blade, and the second passage surface runs at
an incline and widening thereto, and is formed to be limited and
closed circumferentially at least in an axial sub-section facing
the cutting head end by a circumferential wall as third passage
surface, wherein at least one coolant duct, which is provided to
guide coolant to the cutting head end, is formed within the
circumferential wall.
2. The cutting tool according to claim 1, wherein at least one chip
outlet opening is provided in the circumferential wall on an end of
the tool carrier facing the clamping shank.
3. The cutting tool according to claim 2, wherein a chip guiding
surface, which is inclined relative to a longitudinal axis of the
cutting tool and which is formed to guide chips and/or coolant from
the interior of the chip-receiving space to the outside, is
provided in the interior of the chip-receiving space in the region
of the chip outlet opening.
4. The cutting tool according to claim 1, wherein a central coolant
passage is provided in the clamping shank and a base section of the
tool carrier, which coolant passage is connected to the at least
one coolant duct in a transition region between the base section
and the cutting head.
5. The cutting tool according to claim 1, wherein the first passage
surface comprises at least one sub-section of a chip entraining
surface adjoining the blade, and the second passage surface
comprises a surface of a chip guiding section, which extends so as
to be angled or curved at least section by section in the direction
of the clamping shank, in order to widen the chip passage from the
chip gap in the direction of the chip-receiving space.
6. The cutting tool according to claim 5, wherein the blade
comprises a first cutting edge on the axial cutting head end, and a
second cutting edge in the region of the circumferential wall of
the cutting head, wherein the chip gap extends along the first and
the second cutting edge, so that the chip passage is open towards
the circumferential wall of the tool carrier in the region of the
second cutting edge.
7. The cutting tool according to claim 5, wherein the blade has a
chip surface, which forms a sub-section of the first passage
surface, wherein the chip surface runs flush with the first passage
surface.
8. The cutting tool according to claim 5, that wherein the second
passage surface has at least one coolant outlet, which faces the
blade and which is connected to the coolant duct.
9. The cutting tool according to claim 8, wherein the coolant
outlet is formed as groove, which in particular runs parallel to a
head cutting edge of the blade.
10. The cutting tool according to claim 1, wherein the
circumferential wall has a cross sectional widening, which is
directed inwardly, in the region of the cutting head end, wherein
the at least one coolant duct is curved in such a way that coolant
also flows through the cross sectional widening.
11. A production method for a cutting tool according to claim 1,
wherein the tool carrier is produced by means of an additive
manufacturing method, in particular selective laser melting, by
applying material to the clamping shank.
12. The production method according to claim 11, wherein a base
section is provided between the clamping shank and the tool
carrier, which base section has a central coolant duct, wherein the
tool carrier is produced by means of an additive manufacturing
method, in particular selective laser melting, by applying material
to the base section.
13. A production method for a cutting tool according to claim 11,
wherein the additive manufacturing method is selective laser
melting.
14. The production method according to claim 11, wherein a base
section is provided between the clamping shank and the tool
carrier, which base section has a central coolant duct, wherein the
tool carrier is produced by means of selective laser melting, by
applying material to the base section.
Description
[0001] The present invention relates to a cutting tool for
chip-removing production and machining of recesses and/or
depressions of a component to be processed, in particular for
producing or post-processing a plug bore according to the preamble
of claim 1.
PRIOR ART
[0002] Generic cutting tools in the form of milling drills are used
to produce bores, for example water plug bores in internal
combustion engines. Such cutting tools in the form of reamer tools
are further used for fine-processing bores by means of reaming. The
surface quality as well as the dimensional accuracy of bores and
recesses or depressions, respectively, in components to be
processed is improved by means of the reaming process.
[0003] A bore or a recess in a component is usually produced in two
or more operations. In a first operation, a bore or a recess in a
component is initially introduced by means of a spiral drill or a
milling drill, wherein the front and side surfaces of the bore or
recess have a certain roughness. In a second operation, these
surfaces are post-processed to a desired surface quality by means
of a reamer tool, wherein only a few tenths of a millimeter of
material are typically removed and tolerances IT7 to IT5, e.g., can
be attained.
[0004] Water plug bore are provided in particular in engine
construction, in order to provide cooling fluid-guiding recesses in
the engine block. To post-process such water plug bores,
single-stage or multi-stage reamer tools are used, which attain a
high surface quality in the processing of such recesses and boring
surfaces.
[0005] Generic cutting tools typically have blades on the
circumference and/or on the ingate, i.e. on the head end of the
tool. The cutting edges are usually aligned parallel or vertically,
respectively, to an axis of rotation of the cutting tool. Typical
diameters of such cutting tools lie between 1 mm and 50 mm, wherein
the cutting head, which supports the blades, is usually made of
solid carbide (SC).
[0006] Blades made of diamond have been known for a long time. More
recently, a manufacture of blades of a hard crystal material, in
particular a synthetically produced crystal cutting material has
established itself, wherein, for example in the blade, diamond
particles are embedded in a metal matrix, or a boron nitride blade
is used. Diamond blades, PCD blades (polycrystalline diamond
blades) or CBN blades (cubic crystalline boron nitride blades) are
thus used in many cases, which are permanently fastened to the
cutting head by means of soldering or welding or which are
exchangeably attached to the cutting head by means of suitable
fastening means.
[0007] Material chips, which can accumulate at the blades and the
removal of which from the processing location takes place, for
example, by means of coolant flushing or by means of repeated
removal of the cutting tool from the bore and cleaning of the bore,
result in the processing process. A reliable discharge of chips as
part of a continuous processing and without complex cleaning
measures is only possible to an unsatisfactory extent with the
currently known cutting tools. An ultrapure processing of the
engine block interior is strived for especially in a processing of
engine blocks, so that chips are to be discharged reliably.
[0008] A reamer tool is known from WO 2009/071288 A1, which, to
guide chips, has a chip guiding element comprising a guide surface,
which forms a slit-shaped receiving space with a chip surface of
the blade. The chip guiding element is formed in a cuboid shape and
has a flat guide surface, which, with a chip surface connecting to
the cutting insert on the rear, forms a receiving duct, which
adjoins the receiving gap. In this receiving gap, the chips are
deflected and discharged in the direction of a side surface of the
chip space adjacent to the cutting insert.
[0009] DE 10 2005 034 422 A1 discloses a reamer for machining bores
in workpieces, which are difficult to cut. The tool comprises at
least one cutting insert comprising a blade and at least one guide
strip. With the help of the guide strip, the reamer is guided in
the bore, which is to be processed.
[0010] DE 10 2013 114 792 A1 shows a machining tool in the form of
a drill comprising internal cooling and inner chip discharge. The
drill shank is formed cylindrically and has evenly distributed
diamond blades on the front-side end. For the cooling, a plurality
of cooling ducts run in the wall of the drill shank, wherein each
duct has a coolant inflow duct as well as a coolant return duct.
The drill shank is connected to a machine tool via an adapter. A
single coolant inflow duct as well as a single coolant return duct
is arranged in this adapter. The adapter is connected to the drill
shank via a flange connection. The inner chip discharge takes place
via the extraction duct as well as via suction openings, which are
arranged in a side wall of the adapter.
[0011] DE 103 05 991 A1 discloses a milling tool comprising an
extraction device and a tool head. The extraction device is clipped
onto the tool body. The extraction takes place via the extraction
ducts, which run helically in the tool shank, as well as via slits,
which are connected to the blades. The tool head has a central
cooling duct, which divides into individual grooves on the front
side of the tool shank and which is guided to the individual blades
in this way.
[0012] A machining tool as well as a method for producing a
machining tool by means of a 3D printing method are disclosed in DE
10 2014 207 510 A1.
[0013] A further generic cutting tool comprising a chip guiding
element is known from EP 2 839 913 A1.
[0014] It is the object of the invention to create a cutting tool
of the above-mentioned type, which has an improved chip guidance
and which minimizes the risk that chips remain in the processing
space.
DISCLOSURE OF THE INVENTION
[0015] The object is solved by means of a cutting tool comprising
the features of claim 1. Advantageous embodiments of the invention
are the subject matter of the dependent claims.
[0016] The cutting tool according to the invention, in particular
for producing or post-processing a plug bore, comprises a clamping
shank and a tool carrier comprising a cutting head and at least one
blade, which is arranged at an axial cutting head end of the tool
carrier, wherein the tool carrier comprises a chip-receiving space,
which is molded to receive material chips of a component to be
processed removed by the blade.
[0017] It is proposed that a respective chip passage, which feeds
into the chip-receiving space and which is limited by a chip gap,
which runs radially and which is partially limited by the blade,
and from there by a first and second passage surface extending in
the direction of the chip-receiving space, adjoins the at least one
blade, wherein the first passage surface is a continuation of the
chip surface of the blade, and the second passage surface runs at
an incline and widening thereto, and is formed to be limited and
closed circumferentially at least in an axial sub-section facing
the cutting head end by a circumferential wall as third passage
surface, wherein at least one coolant duct, which is provided to
guide coolant to the cutting head end, is formed within the
circumferential wall.
[0018] A cutting tool is created with the present invention, which
has a chip-receiving space, which is completely closed
circumferentially at least in an axial sub-section adjoining the
cutting head end. The closed chip-receiving space has the effect
that material chips, which are lifted off of a cutting edge of the
blade on the component to be processed, are removed reliably from
the processed bore. It is virtually impossible that chips, which
enter into the chip-receiving space, can reach from the latter
axially forwards into the processing region again. It is further
prevented that material chips on the circumferential side of the
cutting tool can come into contact there with the side wall, which
has already been processed, of the bore to be processed. It is
prevented thereby that the material chips can get caught on the
side wall of the component to be processed and can thus possibly
negatively impact the quality of the surface, which has already
been processed.
[0019] To transport chips, which are milled off a cutting of the
cutting insert on the component to be processed, into the
chip-receiving space, a chip guiding passage is arranged in the
region of the cutting insert, which defines a chip passage with
respect to the cutting insert. The chip passage has a chip gap,
into which chips can penetrate.
[0020] A respective chip passage, which feeds into the
chip-receiving space and which is limited by a chip gap, which runs
radially and which is partially limited by the blade, and at least
by a first and a second passage surface extending in the direction
of the clamping shank, as well as by a circumferential wall as
third passage surface, adjoins the at least one blade. The first
passage surface is defined by a chip shoulder of the blade and by
the chip entraining surface adjoining the chip shoulder. The second
passage surface is formed in such a way that it widens the chip
passage in the direction of the clamping shank towards the
chip-receiving space. A funnel, which widens in the direction of
the chip-receiving space, is thus formed, through which material
chips removed by the cutting edge are pushed in the direction of
the chip-receiving space by means of the rotational movement of the
cutting tool, and are guided away from the cutting edge. Chips are
discharged from the processing location into the chip-receiving
space, so that the milling region remains free from chips, no chip
accumulation occurs, and a consistent high quality of the friction
point is attained. An increased heat development is prevented and
the service life of the cutting or reamer tool is increased. A
third passage surface limits the chip passage on the
circumferential side of the cutting tool. The closed chip passage
forms a type of nozzle, which discharged coolant supplied to the
cutting edges, together with the material chips, in the desired
direction. Finally, the risk that material chips inadvertently fall
back into the bore when pulling the cutting tool out of the bore,
and negatively impact function of the component during the
subsequent operation, decreases, which is advantageous in
particular when processing water plug bores in engine blocks.
[0021] The complete cutting head comprising the chip-receiving
space as well as the passage surfaces is preferably formed in one
piece and is preferably produced in one piece. The production of
such an element, which is closed by means of the circumferential
side and which has a chip passage comprising specially formed
passage surfaces in the interior, can take place, for example, by
means of an additive manufacturing method. Such an additive
manufacturing method provides for the production of passage
surfaces of arbitrarily inclined passage surfaces in the interior
of the chip-receiving space.
[0022] One or a plurality of coolant ducts, via which coolant can
be supplied to the cutting head end or to the blades, respectively,
are further formed in the circumferential wall. In the region of
the tool carrier, the at least one coolant duct is preferably not
arranged centrically, i.e. not on the axis of rotation of the tool
carrier. Said coolant duct runs in the circumferential wall, i.e.
in the wall of the hollow cylinder, wherein this hollow cylinder
can be formed variably across the length of the tool carrier. For
example the geometry of the hollow cylinder per se as well as the
wall thickness of the circumferential wall can thus change.
[0023] The coolant duct or ducts cannot only be formed as
tube-shaped or capillary-shaped ducts, but can extend in the
circumferential direction across a significant angular range, for
example by more than one-fourth in total, more than half, or even
more than three-fourths of the total angular range of 360.degree..
Coolant ducts, which can have a relatively small expansion in the
radial direction, for example 2 mm or less, preferably 1 mm or
less, and in particular even 0.5 mm or less, can be created in this
way. The thickness of the circumferential wall can be kept small
thereby, so that the chip-receiving space has the largest possible
cross section, based on the total cross section of the cutting
head, in order to provide for an efficient removal of material
chips. The cutting tool according to the invention thus has a
fluidically favorable chip-receiving space, which also reliably
receives and removes larger material chips. Compared to
conventional cutting tools, which have a central coolant duct and,
according to the number of the blades, often two or more
chip-receiving spaces, which are located radially on the outside
and which are arranged around the coolant duct, the transport even
of larger material chips improves by means of the creation of a
chip-receiving space according to the invention comprising a large
cross section.
[0024] An efficient and also even cooling of the cutting head is
also attained by means of the circumferential wall of the cutting
head, through which coolant flows.
[0025] The blade can be formed as exchangeable blade, in particular
cutting insert, or can be firmly connected, in particular soldered,
to the cutting head. The number of the blades can in particular be
two, wherein cutting tools comprising a larger number of blades,
e.g. three or four, can also be realized. The blades can be
arranged in such a way that they cut over center or also not over
center.
[0026] The distance of the chip outlet opening to the front side of
the cutting head is advantageously chosen in such a way that it is
larger than the maximum depth of the bores in the workpiece, which
are to be processed, so that the chips can escape unhindered.
[0027] The tool carrier is formed in one piece. This means that the
region, comprising the cutting head comprising the circumferential
wall, the chip-receiving space, as well as the chip outlet opening,
is formed in one piece. This complete region consists of a part,
which can be connected to the clamping section, for example
directly. This tool carrier can thus be applied or fastened,
respectively, to any clamping section. This can take place, for
example, by means of an additive manufacturing method, in
particular selective laser melting, by applying material to the
clamping shank.
[0028] Such a cutting tool can be clamped into any machine tools,
wherein cutting cools comprising different diameters or comprising
a chip-receiving space of any diameter, respectively, can be used
flexibly.
[0029] This results from the fact that the tool can be installed in
any receptacles of a machine tool, wherein the clamping shank is
formed independently of the diameter of the chip-receiving space. A
connection region or an additional adapter, respectively, for
discharging the chips is not necessary thereby, because the chip
discharge takes place in the region of the one-piece tool shank,
which has the chip outlet openings. The chip discharge thus takes
place in a region in the length of the tool shank.
[0030] The one-piece design saves the use of connecting means as
well as the presence of connecting joints, whereby a chip discharge
without leakage or unwanted outlet regions, respectively, or loss
draft can be ensured.
[0031] The use of seals, which would be required in the case of
additional connecting regions with additional connecting means, in
order to ensure an optimal chip discharge without losses, can
likewise be saved.
[0032] The blades can furthermore be detachably installed and can
be formed so as not to be in one piece with the tool carrier.
[0033] At least two chip outlet openings, which are preferably
arranged opposite one another in the circumferential wall, are
advantageously provided in the circumferential wall on an end of
the tool carrier facing the clamping shank.
[0034] According to an advantageous embodiment, at least one chip
outlet opening is provided in the circumferential wall on an end of
the tool carrier facing the clamping shank. Coolant and/or material
chips can leave the chip-receiving space again through the chip
outlet opening. The chip outlet opening is preferably formed by a
circumferential sub-section of the circumferential wall. The chip
outlet opening can thereby have the shape of a section of a
cylinder jacket surface. The circumferential geometry of the chip
outlet opening can be formed arbitrarily. It is likewise
conceivable that two chip outlet openings located opposite one
another are arranged in the circumferential wall. A chip discharge,
which is symmetrical with respect to the axis of rotation, from the
chip-receiving space can be attained thereby. The two chip outlet
openings are thereby preferably formed identically.
[0035] Advantageously, two chip outlet openings are provided, which
are located opposite one another and which thus ensure an efficient
removal of chips and/or coolant. The distance of the one or
plurality of chip outlet openings to the front side of the cutting
head is advantageously chosen in such a way that it is larger than
the maximum depth of the bores in the workpiece, which are to be
processed, so that the chips can escape unhindered.
[0036] It has proven to be advantageous in this context, when a
chip guiding surface, which is inclined relative to a longitudinal
axis of the cutting tool and which is formed to guide chips and/or
coolant from the interior of the chip-receiving space to the
outside, is provided in the interior of the chip-receiving space in
the region of the chip outlet opening. The angle of inclination of
the chip guiding surface can be, for example, approximately
45.degree.. The chip guiding surface can in particular also be
curved concavely, wherein the inclination of the chip guiding
surface advantageously increases with respect to a longitudinal
axis of the cutting tool, as the distance to the chip outlet
opening decreases.
[0037] According to a further advantageous embodiment, a central
coolant passage is provided in the clamping shank and a base
section of the tool carrier, which coolant passage is connected to
the at least one coolant duct in a transition region between the
base section and the cutting head. The central coolant passage
guides coolant to the coolant duct or ducts and is formed in such a
way at least in the region of the clamping shank that a
compatibility with a coolant supply of a tool receptacle, into
which the clamping shank can be clamped, is at hand.
[0038] The first passage surface can advantageously comprise at
least one sub-section of a chip entraining surface adjoining the
blade, and the second passage surface can comprise a surface of a
chip guiding section, which extends so as to be angled or curved at
least section by section in the direction of the clamping shank, in
order to widen the chip passage from the chip gap in the direction
of the chip-receiving space.
[0039] According to a further advantageous embodiment, the blade
comprises a first cutting edge on the axial cutting head end, and a
second cutting edge in the region of the circumferential wall of
the cutting head, wherein the chip gap extends along the first and
the second cutting edge, so that the chip passage is open towards
the circumferential wall of the tool carrier in the region of the
second cutting edge. In other words, the chip passage is not
limited in the circumferential direction in the region of the
second cutting edge. It is ensured thereby that the material chips
removed from the second cutting edge, which is provided
circumferentially, can also enter reliably into the chip passage
and are discharged therefrom.
[0040] According to a further advantageous embodiment, the blade
has a chip surface, which forms a sub-section of the first passage
surface, wherein the chip surface runs essentially flush with the
first passage surface. The entire first passage surface is thus
preferably flat, starting at the cutting edge, and runs in
particular parallel to the longitudinal axis of the cutting tool.
The first passage surface, however, can, for example, also have a
step, which supports a chip break.
[0041] According to yet a further advantageous embodiment, the
second passage surface has at least one coolant outlet, which fares
the blade and which is connected to the coolant duct. The coolant
outlet is advantageously formed in such a way that at least a
portion of the escaping coolant hits the cutting edge in order to
cool and to lubricate it. The escaping coolant furthermore supports
a failure-free removal of the material chips.
[0042] The coolant outlet is advantageously formed as groove, which
in particular runs parallel to a head cutting edge of the blade.
Coolant is thereby distributed evenly across the cutting edge. In
addition, one or both edges of the groove can act as chip breaking
edge.
[0043] On principle, a plurality of coolant outlets can also be
provided. Coolant outlets do not mandatorily need to be arranged
only in the second passage surface, but can alternatively or
additionally also be provided at another suitable location.
[0044] According to a further advantageous embodiment, the
circumferential wall has a cross sectional widening, which is
directed inwardly, in the region of the cutting head end, wherein
the at least one coolant duct is curved in such a way that coolant
also flows through the cross sectional widening. The mentioned
cross sectional widening is understood to be an arrangement of
additional material in the interior of the cutting head, so that
the cross sectional surface of the chip-receiving space, thus of
the hollow space, is reduced. The cross sectional widening ensures
a reliable storage of the one or plurality of blades and a reliable
deflection and transfer of the cutting forces to rear regions of
the cutting tool. The flow-through of the cross sectional widening
with coolant can be effected, for example, by means of a
meander-shaped guidance of the coolant duct or ducts, wherein in
particular one or a plurality of sub-sections of the coolant ducts
effect a reversal of the flow direction of the coolant.
[0045] The tool carrier is advantageously produced by means of an
additive manufacturing method, in particular by means of selective
laser melting, by applying material to the clamping shank.
[0046] A production method for a cutting tool according to the
invention is furthermore a subject matter of the invention.
[0047] It is proposed that the tool carrier is produced by means of
an additive manufacturing method, in particular selective laser
melting, by applying material to the clamping shank. Such
manufacturing methods are suitable in particular way to create the
partially complex structures of the tool carrier with manageable
cost and manufacturing expenditure. The non-detachable connection
between tool head or cutting head, respectively, and clamping shank
likewise takes place as pat of the additive manufacture.
[0048] If, on its end located opposite the cutting head end, the
cutting head merges into a base section of an enlarged cross
section, which is connected to the clamping shank, this base
section can likewise be produced by means of the additive
manufacturing method.
[0049] In an advantageous embodiment of the method, a base section
is provided between the clamping shank and the tool carrier, which
base section has a central coolant duct, wherein the tool carrier
is produced by means of an additive manufacturing method, in
particular selective laser melting, by applying material to the
base section. The base section can thereby be formed as described
above and can have the same advantages.
DRAWINGS
[0050] Further advantages follow from the drawing and from the
corresponding description of the drawing. Exemplary embodiments of
the invention are illustrated in the drawing. The drawing, the
description, and the claims include numerous features in
combination. The person of skill in the art will advantageously
also consider these features individually and will combine them to
expedient further combinations.
[0051] FIG. 1 shows a side view of an embodiment of a cutting tool
according to the invention;
[0052] FIGS. 2 and 3 show sectional illustrations of the cutting
tool of FIG. 1 and;
[0053] FIG. 4 shows a perspective view of a further embodiment of a
cutting tool according to the invention;
[0054] FIG. 5 shows a front-side view of the embodiment from FIG.
4;
[0055] FIGS. 6 and 7 show sectional illustrations of the embodiment
according to FIG. 4.
[0056] Identical or similar components are numbered with identical
reference numerals in the Figures.
[0057] FIGS. 1 to 3 show an exemplary embodiment of a cutting tool
10, which can be used, for example, as milling drill or reamer, in
particular as water plug drill. The cutting tool 10 is moved in a
rotational manner in an operational direction of rotation 52 for
processing a component. It comprises a tool carrier 12 and a
clamping shank 14, which can be clamped into a bore shank of a
machine. The clamping shank 14 can in particular be formed as
hollow shank taper for a hollow shank taper receptacle (HSK
receptacle).
[0058] The tool carrier 12 comprises a cutting head 22, which
comprises a central chip-receiving space 26 as well as a cutting
region 28 on the cutting head end 24. This region is formed in one
piece. Two blades 18, which can be sintered, for example, of a PCD
or a CBN material, are fastened to the cutting head end 24. Each
blade 18 has a side cutting edge 42 for cutting or reaming a
circumferential bore surface, a head cutting edge 40 for cutting or
reaming an ingate, and a chamfer cutting edge 38, which is inclined
at an angle of approx. 45.degree., for cutting or reaming a chamfer
of a component.
[0059] On its end opposite the cutting head end 24, the cutting
head 22 merges into a base section 16, which has an enlarged cross
section and which is connected to the clamping shank 14. On this
base section, the cutting head can be produced, for example
directly via an additive manufacturing method, wherein a
non-detachable connection between the base section and the cutting
head likewise takes place by means of this additive manufacturing
method. The base section itself can likewise be produced by means
of the additive manufacturing method and by means of the same
manufacturing step as the cutting head or the tool carrier,
respectively.
[0060] The chip-receiving space 26, which is cylindrical at least
in sections, is defined by a circumferential wall 66, which, in a
region adjoining the base section 16, has two chip outlet openings
54, which are located opposite one another and which provide for an
outlet of material chips and coolant from the chip-receiving space
26. Respective chip guiding surfaces 58, which run at an incline
with respect to the chip outlet openings 54 and which form a type
of wedge and which guide the material chips or the coolant,
respectively, in the direction of the chip outlet openings 54, are
provided in the interior of the chip-receiving space 26.
[0061] As can be seen well in particular in FIG. 2, two coolant
ducts 64, which are connected to a central coolant passage 60,
which is provided in the clamping shank 14 and the base section 16,
are formed in the interior of the circumferential wall 66. The
coolant ducts 64 can extend across the circumference in sectors, so
that the inner and outer wall of the circumferential wall 66 are
only connected there via two relatively narrow webs.
[0062] The cutting region 28 comprises a region, in which the head
cutting edges 40 process the ingate bottom of a depression, as well
as a circumferential region, in which the side cutting edges 42
process a wall surface of the depression. The chamfer cutting edges
38 accordingly process a chamfer surface of the depression. Chips
removed by the cutting edges 38, 40, can each enter through a chip
gap 44 into a respective funnel-like chip passage 50 formed in the
interior of the cutting head 22. Each chip passage 50 is limited by
a first passage surface 46 and a second passage surface 48, and
widens in a cross section in the direction of the clamping shank
14. The chip passages 50 feed into the chip-receiving space 26, so
that chips can be transported through the chip passages 50 into the
chip-receiving space 26.
[0063] As can be seen well in particular in FIG. 2, the chip
surface 30 of the blade 18, together with the chip entraining
surface 32, forms the first passage surface 46. A chip guiding
section 56, which partially comprises an inner surface of the
circumferential wall 66 and partially a second passage surface 48,
which is inclined with respect to the first passage surface 46, is
located opposite the first passage surface 46 or the chip
entraining surface 32, so that the cross section of the chip
passage 50 widens, viewed in the direction of the clamping shank
14.
[0064] In the region of the chip passage or of the chip entraining
surface 32, respectively, the cutting head 22 has a cross sectional
widening 58, which is directed inwards and which serves to fasten
the blades 18 and to deflect the occurring cutting forces. In the
region of this cross sectional widening 68, the coolant ducts 64
are guided in a meander-shaped manner, in order to ensure a
sufficient cooling of the cutting head end 24 and to guide the
coolant to coolant outlets 62, 63. On the one hand, the coolant
ducts 64 feed into a central coolant outlet 63, which is provided
on the front side of the cutting head end 24, via branch ducts,
which are only illustrated in sections, and, on the other hand,
into respective coolant outlets 62, which are provided in the
second passage surface 48 and face a respective blade 18 and which
can be formed as grooves running parallel to the head cutting edge
40. A coolant flow, which serves to lubricate and cool the cutting
edges 38, 40, 42 and simultaneously supports the removal of the
chips, is introduced through the coolant outlets 62, 63.
[0065] The completely closed shape of the chip passages 50 and of
the adjoining chip-receiving space 26 thereby improves the flow
pattern of the coolant-chip mixture and prevents that chips get
caught circumferentially or that coolant escapes circumferentially
from the chip-receiving space 26 or the chip passages,
respectively. The longitudinal edges of the coolant outlets 62
running parallel to the head cutting edges 40 simultaneously act as
chip breaking edges, which can entrain or break chips,
respectively, in order to mold them as small as possible and to
transport them through the chip passage 50 into the rearward
chip-receiving space 26.
[0066] In the case of the cutting tool 10 according to the
invention, an effective removal of chips into a rearward
chip-receiving space 26 is promoted and the durability, the
processing quality, and the operating speed of the cutting tool 10
is thus increased. The coolant ducts 64 running in the
circumferential wall 26 thereby effect an efficient cooling of the
cutting head 22 as well as a coolant supply to the coolant outlets
62, 63, which is efficient due to the large cross section.
[0067] FIGS. 4 to 7 show a further exemplary embodiment of a
cutting tool 10. The cutting tool 10 is moved in a rotational
manner in an operational direction of rotation 52 for processing a
component. It comprises a tool carrier 12 and a clamping shank 14,
which can be clamped into a bore shank of a machine. The clamping
shank 14 can in particular be formed as hollow shank taper
receptacle (HSK receptacle).
[0068] The tool carrier 12 comprises a cutting head 22, which
comprises two central chip-receiving spaces 26 as well as a cutting
region 28 on the cutting head end 24. Two blades 18, which each
have a blade carrier, are screwed to the cutting head end 24. Each
cutting insert 18 has a side cutting edge 42 for reaming a
circumferential bore surface, and a head cutting edge 40 for
reaming an ingate of a component.
[0069] Each chip-receiving space 26 is in each case defined by a
flat chip entraining surface 32 and a chip guiding section 56,
which is angled at a right angle thereto, wherein the chip guiding
surface 58 is curved concavely in the direction of the clamping
shank 14, in order to be able to transport received chips to the
outside outside of the processing region. A removal of the chips
from the processing region is thus attained by means of the chip
guiding surface 58, which points to the outside.
[0070] The cutting region 28 comprises a region, in which the head
cutting edges 40 ream on the ingate bottom of a depression, as well
as a circumferential region, in which the side cutting edges 42
ream a wall surface of a bore or recess. Chips removed by the
cutting edges 40, 42 can in each case enter through a chip gap 44
into a respective duct-like chip passage 50, which is formed in the
interior of the cutting head 22. Each chip passage 50 is limited by
a first passage surface 46 and a second passage surface 48 (both
not visible in this illustration), and by a third passage surface
in the form of the circumferential wall 66, and widens in its cross
section in the direction of the clamping shank 14. The chip passage
50 feeds into the chip-receiving space 26, so that chips can be
transported through the chip passage 50 into the chip-receiving
space 26.
[0071] A chip guiding section 56 of the tool carrier 12 extending
from the cutting head end 24 in the direction of the clamping shank
14 has the shape of a quarter section of a circular cylinder,
wherein the first quartering surface thereof is cut, and the second
quartering surface thereof runs in extension of the chip guiding
section 56.
[0072] As can be seen well in particular in FIG. 7, the chip
guiding surface 30, together with a sub-section of the chip
entraining surface 32, forms the first passage surface 46. The cut
first quartering surface of the chip guiding section 56 runs
opposite the first passage surface 46 and forms the second passage
surface 48, wherein the second passage surface 48 is inclined with
respect to the first passage surface 46, and has a concave
curvature, so that the cross section of the chip passage 50 widens,
viewed in the direction of the clamping shank 14.
[0073] The circumferential wall 66 (cut away in the illustration of
FIG. 7), which can be seen well in FIG. 6, directly adjoins the
first and second passage surface 46, 48, and circumferentially
limits the chip passage 50 to a majority of its length, i.e.
between the chip gap 44 and the chip-receiving space 26. The chip
gap 44 extends along the cutting edges 40, 42, so that the chip
passage 50 is open towards the circumferential side 66 of the tool
carrier 12 in the region of the side cutting edge 42.
[0074] Respective transitions between the passage surfaces 46, 48,
54, 58 can be formed to be edge-shaped or continuously, i.e.
rounded or so as to merge into one another.
[0075] The cutting tool 10 has a coolant duct 66, which is formed
as central axial bore and which extends through the clamping shank
14 and the tool carrier 12. On the one hand, the coolant duct 64
feeds into a central coolant outlet 63 provided on the front side
of the cutting head end 24 via branch ducts, which are not
illustrated in more detail, and, on the other hand, into a
respective coolant outlet 62, which is provided in the second
passage surface 48 and which faces the cutting insert 18 and which
is formed as groove running parallel to the head cutting edge 40. A
coolant flow, which serves to lubricate and cool the cutting edges
40, 42 and simultaneously supports the removal of the chips, is
introduced through the coolant outlets 62, 63.
[0076] The closed shape of the chip passage 50 thereby improves the
flow pattern of the coolant-chip mixture and prevents that chips
get caught circumferentially or that coolant escapes
circumferentially from the chip passage 50. The longitudinal edges
of the coolant outlets 62 running parallel to the head cutting
edges 40 simultaneously act as chip breaking edges, which can
entrain or break chips, respectively, in order to form them as
small as possible and to transport them through the chip passage 50
into the rearward chip-receiving space 26.
[0077] In the case of the cutting tool 10 according to the
invention, an effective removal of chips into a rearward
chip-receiving space 26 is promoted and the durability, the
processing quality, and the operating speed of the cutting tool 10
is thus increased.
REFERENCE LIST
[0078] 10 cutting tool [0079] 12 tool carrier [0080] 14 clamping
shank [0081] 16 base section [0082] 18 blade [0083] 22 cutting head
[0084] 24 cutting head end [0085] 26 chip-receiving space [0086] 28
cutting region [0087] 30 chip surface [0088] 32 chip entraining
surface [0089] 38 chamber cutting edge [0090] 40 head cutting edge
[0091] 42 side cutting edge [0092] 44 chip gap [0093] 46 first
passage surface [0094] 48 second passage surface [0095] 50 chip
passage [0096] 52 operational direction of rotation [0097] 54 chip
outlet opening [0098] 56 chip guiding section [0099] 58 chip
guiding surface [0100] 60 coolant passage [0101] 62, 63 coolant
outlet [0102] 64 coolant duct [0103] 66 circumferential wall [0104]
68 cross sectional widening
* * * * *